Which culture result would lead an infection preventionist to question whether the proper methods were used when collecting and labelling the sample that was tested?

• A. Anisakis simplex from a patient who ate sushi the night before
• B. Babesia divergens from a patient who has undergone a splenectomy
• C. Babesia divergens from a patient admitted the night before to the emergency department with a swollen ankle and possible tick bite
• D. Anisakis simplex from a deep wound on the patient's right arm

Answer: (D)

When a lab result doesn’t fit how a pathogen is typically acquired or where it’s usually found, it raises a red flag about how the specimen was collected or labeled. Anisakis simplex is a parasite people get from eating raw or undercooked fish, and it isn’t something you’d expect to identify in a deep wound on the arm. Seeing it there would be highly unlikely and would make an infection preventionist question whether the sample truly came from the wound patient, or if there was mix-up or contamination during collection or labeling. In contrast, the other scenarios align with known exposure routes or specimen types—for example, Anisakis linked to sushi reflects ingestion exposure, and babesiosis identified in blood samples is plausible for a tick-borne infection, especially in a splenectomized patient. The deep-wound finding is the most suspicious for proper collection and labeling being in doubt.